Reactor packing

ABSTRACT

A structured packing for insertion in a reactor having an inlet, an outlet, a wall and an axis. The packing comprises a first part, i.e., a reactor core and a second part, i.e., a reactor casing. The second part is free to move relative to the first part. The first part and the second part are inserted in the reactor such that the first part is located proximate the axis and the second part is located between the first part and the reactor wall. In general, the second part will be in contact with the reactor wall.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/453,275, filed Apr. 23, 2012, which claims priority of U.S.Provisional Application Ser. No. 61/518,703 filed May 10, 2011 and U.S.Provisional Application Ser. No. 61/626,201 filed Sep. 22, 2011, theentire contents of each of which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention pertains to a structured packing for a reactor.

BACKGROUND OF THE INVENTION

Random reactor packings provide good heat transfer between a reactorwall and fluid passing through the reactor. The particles in the packingrandomly direct the fluid to flow in various directions, includingimpingement upon the reactor wall. Such impingement results in anincrease in the heat transfer coefficient across the boundary layer atthe reactor wall. The diversion of fluid to impinge the wall of areactor while the bulk of the fluid generally flows parallel to the wallof the reactor is most effective when the packing is closest to, orpreferably in contact with, the wall, as this interrupts fluid fromflowing parallel to the wall, which would otherwise cause the heattransfer coefficient across the boundary layer to be relatively low.

Random packings have the advantage over structured packings in that theparticles are free to move relative to each other to fill gaps betweenthe particles and between the particles and the reactor wall. Such gapsare undesirable in that they lower the coefficient of heat transferbetween the reactor wall and fluid within the reactor.

Structured packings have advantages over random packings in that theymay have a higher void volume than random packings. Such higher voidvolume associated with structured packings results in a lower pressuredrop. Structured packings can also be designed to direct fluid to flowin the most advantageous directions for enhancement of heat transferbetween the reactor and its environment. Such advantageous directionsare, e.g., normal to the reactor wall, towards the wall to impinge uponit, or away from the wall to balance the mass flow to and from the wall.

Structured packings can be designed to have a certain distance, space orgap between the packing and the inner reactor wall to facilitateinsertion of the packing into the reactor. Structured packings designedto have such gaps may incorporate separate internal mechanical devicesto move in an outward radial direction to force the outer portion of thestructured packing to move toward the reactor wall. Structured packingsalso are more prone to separate from the reactor wall, thereby resultingin a lower heat transfer coefficient through the boundary layer at thewall than when there is no gap.

OBJECTS OF THE INVENTION

It is an object of the invention to provide a structured packing therebyimproving the transfer of heat between the reactor and its environment.

It is a further object of the invention to provide a structured packingthat will result in a reduction of pressure drop across the reactor.

It is yet another object of the invention to provide a structuredpacking that will maintain contact with, or a close tolerance to, thereactor wall during the insertion of the structured packing into thereactor and throughout the service life of the reactor without anyinternal device moving in a radial direction to force the outer portionof the structured packing toward the reactor wall.

The foregoing objects and other objects will be apparent to thoseskilled in the art based upon the disclosure set forth below.

SUMMARY OF THE INVENTION

A structured packing is provided for use in a reactor having an inlet,an outlet, a wall and an axis. Preferably, the reactor has a tubularconfiguration. The reactor may be a catalytic reactor in which at leastpart of the structured packing is coated with a catalyst suitable forthe reaction that is to take place within the reactor.

The packing comprises a first part and a second part wherein the secondpart is free to move relative to the first part such that movement ofthe second part relative to the first part results in an increase of thediameter of the second part.

The first part, i.e., the reactor core, is located proximate the reactoraxis and is substantially rigid. The second part, i.e., the reactorcasing, is located between the core and the reactor wall and issufficiently flexible to assume an outer dimension that conforms to thereactor wall.

Preferably, the first part has at least one outer surface and/or outeredge oriented at an oblique angle to the reactor wall and in which thesecond part can move along the outer surface and/or outer edge.Typically, movement of the second part along the outer surface and/orouter edge causes the second part to change its outer peripheral length.The oblique angle may have a value of about 1 to about 80°, preferably 5to 35°.

It is preferred the second part have at least one inner surface and/orinner edge oriented at an oblique angle to the reactor wall and suchthat the first part can move along the inner surface and/or inner edge.Typically, movement of the first part along the inner surface and/orinner edge causes the second part to change its outer peripheral length.The oblique angle may have a value of about 1 to about 80°, preferably 5to 35°.

Preferably, the reactor tube and axis are vertical, the first part isstationary and the second part is induced to move downward by the forcesof gravity and differential pressure of downward-flowing fluid throughthe reactor to cause the second part to approach, and preferablycontact, the reactor wall.

Alternatively, the motion of the second part to the first part could bein a direction other than axial to effect the expansion of the secondpart. An example of such alternative motion is a spiral or helicalmovement.

Preferably, reactor is a catalytic reactor and at least part of thepacking will be coated with a catalyst suitable for the reaction that isto be carried out in the reactor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of one of the embodimentsof the invention.

DETAILED DESCRIPTION OF THE DRAWING

Referring to FIG. 1, structured packing 1 is contained within a reactorhaving a wall 2. Packing 1 consists of a series of modules 3 and 4mounted on central rod 5 which rests on support platform 6 (rod 5 andplatform 6 are illustrated as a cross-hatched area). Each moduleconsists of a sleeve 7 (shown as a gray area) which is a thick-walledcylindrical member having a conical base 8 affixed to its bottom region,a core 9 (illustrated by dotted areas) and a casing 10.

Modules 3 and 4 slide onto rod 5 and nest within each other to fill thereactor volume. Core 9 consists of a series of nested, alternatingsmooth and corrugated cones (the corrugated cones act as standoffsbetween the smooth cones). The smooth and corrugated cones may beperforated to permit the flow of fluid through them or they may be solidto impede or prevent the flow of fluid through core 9.

Core 9 and casing 10 abut each other along edges and/or surfaces whichare at an oblique angle to wall 2 in the form of frusto-conicalsurfaces. Core 9 is substantially rigid. Casing 10 is sufficientlyflexible to be capable of both circumferential and radial expansion. Byway of example, casing 10 may be a corrugated sheet in which thecorrugations are aligned with the axis of the reactor and the amplitudeof the corrugations is the distance from wall 2 to core 9. By way offurther example, casing 10 is wrapped around core 9 and contains obliquecutouts as depicted by line 11 at its inner surface to form edges thatabut the oblique upper surfaces of smooth cones (shown by lines 12 incore 9). Alternatively, casing 10 may consist of the type of packingthat is disclosed in published patent application US 2010-0202942 A1which is incorporated herein by reference in its entirety.

All components of the reactor are metal. The sheets are preferably metalfoil. The metal foil or other parts of the packing preferably arepartially or fully coated with a catalyst suitable for the particularreaction that is to occur within the reactor.

The reactor is oriented vertically. Fluid flows downward through thereactor from inlet 13 to outlet 14. Rod 5, sleeve 7, cone 8 and core 9are stationary. Casing 10 can be forced downward by both by gravity andthe differential pressure of the moving fluid to slide down the obliqueedges to thereby cause the outer surface or perimeter 15 of casing 10 tocontact reactor wall 2.

The following three embodiments refer to the reactor in FIG. 1 whereinthe core 9 is rigid and the casing 10 is flexible and is preferablyconstruct of sheet metal which has sufficient elasticity to enable boththe diameter and outer perimeter of casing 10 to be compressed orexpanded in outer perimeter length. In the three embodiments discussedbelow, core 9 and/or casing 10 will typically be partially or completelycoated with a catalyst suitable for carrying out the desired reactionwithin the reactor.

In a first embodiment, casing 10 is of outer perimeter length such thatwhen no force is applied to the casing and prior to its insertion in thereactor, the outer perimeter length is greater (e.g., by about 1 toabout 5%) than the inside circumference of the reactor in which casing10 is inserted. Casing 10 is then squeezed to an outside diameter equalto the inside diameter of the reactor, core 9 is then positioned withrespect to casing 10 so as to abut inside surfaces or edges of casing 10at that outside diameter of casing 10 equal to the inside diameter ofthe reactor, and casing 10 and core 9 are then inserted as a unit intothe reactor.

In a second embodiment, casing 10 is of outer perimeter length such thatwhen no force is applied to the casing and prior to its insertion in thereactor, the outer perimeter length is equal to the inside circumferenceof the reactor in which casing 10 is inserted. Thus, casing 10 will havean outside diameter equal to the inside diameter of the reactor. Core 9is then positioned with respect to casing 10 so as to abut insidesurfaces or edges of casing 10 at that outside diameter of casing 10equal to the inside diameter of the reactor, and casing 10 and core 9are then inserted as a unit into the reactor.

In a third embodiment, casing 10 is of outer perimeter length such thatwhen no force is applied to the casing and prior to insertion in thereactor, the outer perimeter length is less (e.g., by about 1 to about5%) than the inside circumference of the reactor in which casing 10 isinserted. Casing 10 is then expanded to an outside diameter equal to theinside diameter of the reactor. Core 9 is then positioned with respectto casing 10 so as to abut inside surfaces or edges of casing 10 at thatoutside diameter of casing 10 equal to the inside diameter of thereactor, and casing 10 and core 9 are then inserted as a unit into thereactor.

Although the present invention has been described in terms of severalembodiments, various features of separate embodiments can be combined toform additional embodiments not expressly described. Moreover, otherembodiments within the scope of the present invention will be apparentto those skilled in the art. The only limitations on the scope of theinvention are those expressly set forth in the claims which follow.

What is claimed is:
 1. A structured packing for insertion in a reactorhaving an inlet, an outlet, a wall and an axis, said packing comprisinga first part and a second part wherein at least one of: the first parthas at least one outer surface and/or outer edge oriented at an obliqueangle to the reactor wall and in which the second part can move alongsaid outer surface and/or outer edge, and the second part is free tomove relative to the first part, and wherein the second part has atleast one inner surface and/or inner edge oriented at an oblique angleto the reactor wall and in which the first part can move along saidinner surface and/or inner edge.
 2. The packing of claim 1 wherein thefirst part and the second part are insertable in the reactor such thatthe first part is located proximate the axis and the second part islocated between the first part and the reactor wall.
 3. The packing ofclaim 2 wherein the second part is in contact with the reactor wall. 4.The packing of claim 2 wherein prior to insertion in the reactor, thesecond part has an outer peripheral length greater than the innercircumference of the reactor wall.
 5. The packing of claim 4 wherein theouter peripheral length of the second part is about 1 to about 5%greater than the inner circumference of the reactor wall.
 6. The packingof claim 2 wherein prior to insertion in the reactor, the second parthas an outer peripheral length equal to the inner circumference of thereactor wall.
 7. The packing of claim 2 wherein prior to insertion inthe reactor, the second part has an outer peripheral length of less thanthe inner circumference of the reactor wall.
 8. The packing of claim 7wherein the outer peripheral length of the second part is about 1 toabout 5% less than the inner circumference of the reactor wall.
 9. Thepacking of claim 1 wherein the movement of the second part along theouter surface and/or outer edge causes the second part to change itsouter peripheral length.
 10. The packing of claim 1 wherein the obliqueangle has a value of about 1 to about 80°.
 11. The packing of claim 10wherein the oblique angle has a value of 5 to 35°.
 12. The packing ofclaim 1 wherein the movement of the first part along the inner surfaceand/or inner edge causes the second part to change its outer peripherallength.
 13. The packing of claim 1 wherein the reactor is a catalyticreactor and at least part of the packing is coated with a catalystsuitable for the reaction that is to be carried out in the reactor. 14.A structured packing for insertion in a reactor having an inlet, anoutlet, a wall and an axis, said packing comprising a first part and asecond part wherein the second part is free to move relative to thefirst part, and wherein the first part has at least one outer surfaceand/or outer edge oriented at an oblique angle to the reactor wall andin which the first part can move along said outer surface and/or outeredge.